Forster distance Fluorescence resonance energy transfer

Deniz A A, Dahan M, Grunwell J R, Ha T, Faulhaber A E, Chemla D S, Weiss S and Schultz P G 1999 Single-pair fluorescence resonance energy transfer on freely diffusing molecules observation of Forster distance dependence and subpopulations Proc. Natl Acad. Sc/. USA 96 3670-5... 

Here the chromophores can be farther apart (10-100 A long-range interactions) since this mechanism does not require any overlapping of orbitals. The Forster radius designates the distance between donor and acceptor at which the efficiency of energy transfer amounts to exactly 50%. Half of the excited donor molecules are then deactivated by fluorescence resonance energy transfer, and the other 50% by fluorescence or phosphorescence. 

Deniz, A. A., Dahan, M., Gmnwell, J. R., Ha, T., Faulhaber, A. E., Chemla, D. S., Weiss, S., and Schultz, P. G. (1999). Single-pair fluorescence resonance energy transfer on freely diffusing molecules Observation of Forster distance dependence and subpopulations. Proc. Natl. Acad. Sci. USA 96, 3670—3675. 

Forster s theory [1], has enabled the efficiency of EET to be predicted and analyzed. The significance of Forster s formulation is evinced by the numerous and diverse areas of study that have been impacted by his paper. This predictive theory was turned on its head by Stryer and Haugland [17], who showed that distances in the range of 2-50 nm between molecular tags in a protein could be measured by a spectroscopic ruler known as fluorescence resonance energy transfer (FRET). Similar kinds of experiments have been employed to analyze the structure and dynamics of interfaces in blends of polymers. 

Saini S, Singh H, Bagghi B. Fluorescence resonance energy transfer (FRET) in chemistry and biology Non-Forster distance dependence of the FRET rate. J. Chem. Sci. 2006 118 23-35. Schrodinger E. Energieaustausch nach der Wellenmechanik. Ann. Physik. 1927 83 956-968. 

Fluorescence resonance energy transfer (FRET) is a powerful method for the determination of macromolecular conformation and folding in solution [188, 190-194]. The method relies on the incorporation into the macromolecule of a donor dye molecule and an acceptor dye molecule that undergo singlet-singlet Forster energy transfer, which is distance dependent over the 10-100 A range [190-194]. Early work in the field focused on probes noncovalently associated with the macromolecule, but covalent attachment of probes, while harder to do,... 

Fluorescence resonance energy transfer (FRET) experiments commonly use the fluorescent spectrum and relaxation times of the Forster donor and acceptor chromophores to find the distances between fluorescent dyes at labeled sites in protein, DNA, RNA, etc. FRET is a type of spectroscopic ruler . The computation uses either experimental quantum yields or relaxation lifetimes to calculate the efficiency of resonance energy transfer Ej. 

Fluorescence Resonance Energy Transfer (FRET), Table 1 Approximate Forster distances for three common FRET pairs... 

Forster (fluorescence) resonance energy transfer (FRET) is the non-radiative energy transfer mechanism between donor chromophore in its excited electronic state and an acceptor chromophore. FRET is extremely sensitive to small distances as the energy transfer is inversely proportional to the distance between the donor and acceptor chromophore to the sixth power, making it highly suitable for imaging and sensing in biomedical. 

Fluorescence (or Forster) resonance energy transfer (FRET) (Forster, 1948 Perrin, 1932) provides a spectroscopic way of estimating distances over a size range that is appropriate for biological macromolecules. It is based upon fluorescence, one of the most sensitive spectroscopic methods. Fluorescence is the emission of light from an excited molecule, having lost... 

They found that Forster s theory of resonance energy transfer was applicable to such systems if the Interchromophoric distance and orientation, the fluorescence efficiency of the donor, the extinction of the acceptor, and the overlap between the emission of the donor and the absorption of the acceptor are of magnitudes which produce a transfer rate constant of less than 10 s and a transfer efficiency which is not too close to 0 or 1. 

In the case of Forster resonance energy transfer (FRET) [13], i.e. energy transfer by the dipole-dipole mechanism, and for randomly oriented donor-acceptor pairs, the depolarization after one transfer step (ensemble average) is almost complete [27]. For this reason, fluorescence anisotropy is a good indicator of energy transfer between identical fluorophores, hence of relative distances. Existence of efficient FRET may therefore reflect an association process. 

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